BLUE G RFFN RED ' WHITE 



i j k I 



Fig. 9. AcTiox of Different Light Rays 



ON COLEUS AND ON LeTTUCE, 



a. Full radiation, h. red rays, c. green rays, 

 d. blue rays, e. open air, f. subdued light, g. 

 diffused light, h. very dim light, t. _ blue light, /. 

 green light, k. red light, /. white light (a-/ after 

 Flammarion). 



